IF YOU'RE GOING...

Some 90 million years of brute geology created the majestic granite monolith at the eastern end of Yosemite Valley, and more than 150 years of art and photography have made it the global icon of a great national park. Declared “perfectly inaccessible” by a 19th-century geologist, Half Dome’s 8,836-foot summit now offers bragging rights to hikers who reach it by way of switchback trails and a vertigo-inducing cable route and to climbers who crawl straight up the sheer rock.

THREE-FIFTHS DOME? Geologists believe Half Dome was never actually a full dome and that only 30 to 40 percent of the monolith was lost when its glacier-weakened face sheared away.

FEAR FACTOR In 2008, Backpacker magazine named the strenuous yet popular route up Half Dome one of the country’s 10 most dangerous hikes.

ROLLING STONES On March 28, 2009, rock falling from Ahwiyah Point near Half Dome hit the valley floor with as much impact as a magnitude 2.4 earthquake.

OBJECT LESSONNative American legend holds that the Creator punished a quarreling couple by turning them to stone, the wife as Half Dome and the husband North Dome, and setting them on opposite walls of Yosemite Valley.

Photography courtesy wikipedia.org

This article was first published in January 2011. Some facts may have aged gracelessly. Please call ahead to verify information.

If You're Going:

Half Dome is in Yosemite National Park, 195 miles east of San Francisco. When the cable route to the summit is open (late May through mid-October), permits are required daily. (209) 372-0200, nps.gov/yose.